JPH1182876A - Internal combustion engine - Google Patents

Abstract

(57) Abstract: In an internal combustion engine in which an intake port opens toward an opening of a rocker cover, a seal member between a peripheral edge of the opening and the intake port member and a seal member between the intake port member and the intake manifold are provided. Provided is an internal combustion engine that can be shared and that can achieve cost reduction and improvement in assembly workability. SOLUTION: A seal member (92) is attached to a peripheral edge (91) of an opening (90) of a rocker cover (6) so as to sandwich the peripheral edge (91) from above and below, and is provided on a cylinder head (4). Second flange portion (82) on the upper end side of the auxiliary port member (80)
Are made to abut on this seal member over the entire circumference, and the third flange portion (86) of the intake manifold (84)
Are connected to the second flange portion so as to sandwich the seal member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine mounted on a vehicle, and more particularly to a technique for disposing a seal member used in an internal combustion engine.

[0002]

2. Related Background Art In recent years, in a spark ignition type internal combustion engine mounted on a vehicle, fuel is directly injected into a combustion chamber in place of a conventional intake pipe injection type in order to reduce harmful exhaust gas components and improve fuel efficiency. Various types of in-cylinder injection type gasoline engines have been proposed. In such a direct injection gasoline engine, for example, the intake port is formed as a port extending upright in the cylinder head, so that intake with high intake efficiency is performed and a vertical swirl vortex with good combustion efficiency is formed in the combustion chamber. Can be created.

[0003]

In the direct injection gasoline engine as described above, the intake port member extends upright, and the intake port is disposed so as to open toward the opening provided in the rocker cover. Have been. Then, in order to ensure airtightness between the space inside the rocker cover and the outside in the opening, a seal member is usually provided between the periphery of the opening and the intake port member.

[0004] An intake manifold is connected to the intake port member, and a seal member is interposed between the intake port member and the intake manifold to ensure airtightness between the intake port and the intake passage and the outside. I have. However, the connection between the intake port member and the intake manifold is generally close to the opening, and therefore, a seal member between the periphery of the opening of the rocker cover and the intake port member and a seal member between the intake port member and the intake manifold. Providing the members separately is not advisable from the viewpoints of parts cost and assembling workability. This problem is particularly remarkable in an internal combustion engine having a large number of cylinders.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an internal combustion engine in which an intake port is opened facing an opening of a rocker cover. It is an object of the present invention to provide an internal combustion engine capable of realizing cost reduction and improvement of assembly workability by sharing the seal member and the seal member between the intake port member and the intake manifold.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a sealing member is provided on the peripheral edge of the rocker cover so as to sandwich the peripheral edge of an opening hole formed in the rocker cover from above and below. The second flange portion on the upper end side of the auxiliary port member provided on the cylinder head abuts on the seal member over the entire circumference, and the third flange portion of the intake manifold sandwiches the seal member with the third flange portion. It is connected to two flanges.

Therefore, one seal member ensures airtightness between the space between the cylinder head and the rocker cover and the outside, and prevents leakage of oil mist and blow-by gas of the lubricating oil for the valve gear into the atmosphere. At the same time, the airtightness between the auxiliary port of the auxiliary port member and the intake passage of the intake manifold and the outside is ensured, and the number of seal members is reduced while maintaining high sealing performance, thereby reducing costs and improving assembly workability. .

Further, since the periphery of the opening is held between the seal members, the vibration of the rocker cover accompanying the vibration during operation of the internal combustion engine is favorably absorbed by the seal member, and the rocker cover is connected to the auxiliary port member during operation. And contact noise with the intake manifold is prevented. Further, since the periphery of the opening is held between the sealing members, the space between the cylinder head and the rocker cover is airtight even when the periphery of the opening does not form a perfect plane and is wavy. Sex is reliably achieved.

According to the second aspect of the present invention, since the peripheral edge of the opening is sandwiched between the second flange portion of the auxiliary port member and the third flange portion of the intake manifold together with the seal member, the rocker cover is separately fastened at the peripheral edge. Satisfactorily fixed to the cylinder head side without using

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, there is shown a longitudinal sectional view of an internal combustion engine according to the present invention mounted on a vehicle. Hereinafter, the internal combustion engine according to the present invention will be described with reference to FIG. As shown in FIG.
For example, it is a SOHC (single overhead camshaft) in-cylinder injection gasoline engine composed of four valves and four cylinders. The SOHC type is configured so that fuel can be directly injected into the cylinders of all four cylinders. The fuel can be injected not only in the intake stroke but also in the compression stroke.

As shown in FIG. 1, an SOHC type direct injection gasoline engine (hereinafter simply referred to as an engine) 1 is mounted on a cylinder block 2 via a gasket (not shown), similarly to a normal gasoline engine. The cylinder head 4 is fixed by bolts or the like. A rocker cover 6 made of, for example, a steel plate (plate-like member) is mounted on the cylinder head 4 and is also fixed with bolts or the like. More specifically, an endless seal member 7 is attached to the periphery of the rocker cover 6, that is, the rocker cover 6 is attached to the cylinder head 4 via the seal member 7. Thereby, the airtightness of the rocker chamber 6a, which is the internal space of the rocker cover 6, is ensured.

As shown in FIG. 1, a piston 12 is fitted into a cylindrical cylinder 10 of the cylinder block 2. This piston 12 is connected to a connecting rod 14
And slides in the cylinder 10 according to the rotation of the crankshaft to reciprocate. In addition, on the top surface of the piston 12,
Although a cavity 16 which is a hemispherical depression is formed, a detailed description is omitted here.

On the other hand, the cylinder head 4 is provided with a fuel injection valve (injector) 22 for directly injecting fuel toward a combustion chamber 20 formed by being divided by the lower surface of the cylinder head 4 and the top surface of the piston 12. Is provided.
The allowable fuel injection pressure of the fuel injection valve 22 is set to a high pressure (e.g., during the compression stroke in which the pressure in the combustion chamber 20 becomes high). 50 kgf / cm ² or more).

An intake port 34 is formed in the cylinder head 4 and is branched into a Y-shape. More specifically, the lower surface of the cylinder head 4 is located on one side of a base surface (plane) including the longitudinal axis of the engine 1 connecting the cylinder axis X and the central axis of each cylinder. , 30
The lower end (one end) of the pair of branch port portions 34a, 34a is open at the pair of intake ports 30, 30 facing the combustion chamber 20, while the upper end (the other end) is formed. ) Constitute one port portion 34 b in the cylinder head 4.

The cylinder head 4 also has Y
An exhaust port 36 branched in a letter shape is formed. Specifically, a pair of exhaust ports 32, 32 are formed on the lower surface of the cylinder head 4 on the other side of the base surface, and the exhaust port 36 is formed by a pair of branch port portions 36a, 36a.
One end of the cylinder head 4 is open at the pair of exhaust ports 32, 32 facing the combustion chamber 20, while the other end is open at the side surface of the cylinder head 4.

The intake ports 30, 30 have branch port portions 34, respectively.
a, 34a are provided with a pair of intake valves 40, 40 for communicating and blocking between the combustion chamber 20 and the exhaust port 3.
A pair of exhaust valves 42, 42 for communicating and shutting off the communication between the branch ports 37, 37 and the combustion chamber 20 are provided in the ports 2, 32. As shown in the drawing, the intake valves 40, 40 and the exhaust valves 42, 42 are connected to the intake ports 40, 40 and the exhaust port 4 respectively.
Similarly to the positional relationship between the cylinder heads 2 and 42, the cylinder head 4 is provided so as to sandwich the base surface. These intake valves 40, 40 and exhaust valves 42, 42 are not special,
It is commonly used in internal combustion engines.

The cylinder head 4 includes the engine 1
A camshaft (valve operating device) 60 is rotatably supported along the center line in the longitudinal direction.
Specifically, the camshaft 60 is supported on a plurality of shaft support portions 62 formed between the cylinders and at both ends of the cylinder head 4, and further, cam caps 64 provided corresponding to these support portions 62 are provided. And rotatably supported by the cylinder head 4. In addition, a reinforcing plate 65 is passed over each cam cap 64, and each cam cap 64 and the plate 65 are fastened and fixed to the support portion 62 by a pair of bolts.

The camshaft 60 has a pair of cam portions 60a, 60a and 60a so as to correspond to the intake valves 40, 40 and the exhaust valves 42, 42, respectively.
b is formed. And, these cam parts 60a, 6
A pair of rocker arms (valve operating devices) 70, 70 are provided between the cam portion 60 b and the exhaust valve 4.
A rocker arm (valve driving device) 72 having a Y-shape as viewed from the cylinder axis X direction is provided between the rocker arm 2 and 42.

More specifically, as shown in FIG. 2, a rocker shaft 74 and a rocker shaft 76 are supported by the cam cap 64 in parallel with the camshaft 60.
The rocker arms 70, 70 and the rocker arm 72 are swingably supported by the rocker shaft 74 and the rocker shaft 76, respectively. Therefore, the camshaft 60
Is rotated, the rocker arms 70 and 72 follow the shapes of the cam portions 60a and 60b and the rocker shafts 74 and 7 are moved.
As a result, the intake valves 40 and 40 and the exhaust valves 42 and 42 open and close against the urging force of the coil spring.

The cylinder head 4 has a combustion chamber 20.
The ignition plug (ignition plug) 100 is mounted through the guide tube 104 so that the spark generating portion protrudes at substantially the center, that is, the ignition position where the air-fuel mixture in the combustion chamber 20 can be burned most effectively. On the upper surface of the rocker cover 6, an ignition coil 106 for supplying a high voltage current to the ignition plug 100 is provided.

The upper surface of the rocker cover 6 extends integrally with the rocker cover 6 along the longitudinal center line of the engine 1 and between the ignition coil 106 and an intake manifold 84 described later. Thus, a PCV-breather chamber 110 is formed. PCV-breather room 11
0 indicates that the cylinder 10 and the piston 1
2 to separate the unburned fuel leaking from the gap between the fuel cell 2 and the lubricating oil component in the blow-by gas (gas-liquid separation) and supply only the fuel component to the intake system. It was done.

Further, as shown in FIG. 3, auxiliary port members 80 are mounted on the upper surface of the cylinder head 4 corresponding to the respective cylinders, and a flange portion (first flange portion) 81 is fixed by bolts or the like. In addition, an auxiliary port 80a is formed inside the auxiliary port member 80. Auxiliary port 80a
The lower end communicates with the intake port 34 while extending toward the upper surface of the rocker cover 6 so as to be gradually separated from the cylinder axis X. The upper end is opened at the upper surface position of the rocker cover 6. Specifically, an opening hole 90 is formed on one side of the base surface corresponding to each cylinder on the upper surface of the rocker cover 6, and an upper end flange portion (second flange portion) 82 of the auxiliary port member 80 is provided. It fits in the opening hole 90. Actually, the periphery 91 of the opening 90 of the rocker cover 6
An endless annular seal member 92 is fitted into the upper end flange portion 82a. The seal member 92 fits into a step 82a formed on the upper end flange portion 82.
Are fitted into the opening 90 via the seal member 92.

Referring to FIG. 2, there is shown a sectional view of the seal member 92. Referring to FIG. 2, the seal member 92 will be described in detail. The seal member 92 is formed of, for example, elastic rubber material. The seal member 92 has a constant depth over the entire circumference from the outer peripheral side surface 92a to the inner peripheral side surface 92a.
A groove (cut) 93 extending toward b is formed. That is, the seal member 92 is configured as an elastic member having a U-shaped cross section that opens on the outer peripheral side surface 92a. The seal member 92 is fitted into the peripheral edge 91 such that the peripheral edge 91 of the opening hole 90 is inserted into the groove 93.

Therefore, referring to FIG. 3, there is shown a view in which the upper end flange portion 82 fitted into the opening hole 90 is viewed from the direction of arrow A in FIG. The peripheral edge 91 is satisfactorily held by the peripheral edge 91, and the space between the peripheral edge 91 and the upper end flange portion 82 is uniformly sealed over the entire circumference. Thereby, the rocker chamber 6a around the opening hole 90 is formed.
The airtightness between the inside and the outside is ensured, and leakage of oil mist and blow-by gas of lubricating oil scattered in the rocker chamber 6a to the atmosphere is prevented.

An intake manifold 84 is provided at the upper end flange portion 82 of the auxiliary port member 80 with a flange portion (third portion).
A plurality of bolts 85 are connected at a flange portion 86, and the internal passage 84a of the intake manifold 84 communicates with the auxiliary port 80a. Here, the flange portion 86 of the intake manifold 84 and the upper end flange portion 82 (the step portion 82 a) of the auxiliary port member 80 are connected to the seal member 9.
2 so that the internal passages 84a
Further, airtightness between the auxiliary port 80a and the outside is ensured.

That is, the seal member 92 ensures the hermeticity of the rocker chamber 6a around the opening hole 90 and also ensures the hermeticity of the internal passage 84a and the auxiliary port 80a. Therefore, in the internal combustion engine of the present invention,
By using the seal member 92, it is possible to simultaneously secure the airtightness of the three spaces efficiently with one component with high sealing properties, and to reduce the number of seal members and to manufacture the engine 1 at low cost. The workability of assembling the engine 1 can be improved.

In the internal combustion engine of the present invention, a groove 93 is provided in the seal member 92, and a peripheral edge 91 of the opening 90 of the rocker cover 6 is inserted into the groove 93 so that the peripheral edge 91 is sandwiched by an elastic member. . Therefore, the rocker cover 6 can be prevented from contacting the auxiliary port member 80 or the intake manifold 84 at all, and even if the engine 1 vibrates, the contact noise between these members can be prevented. The vibration of the rocker cover 6, that is, the film vibration, can be absorbed by the elasticity of the seal member 92, and the noise generated by the rocker cover 6 can be suitably prevented without using an expensive damping steel plate.

Further, as described above, the peripheral edge 91 of the opening hole 90 is formed.
Is sandwiched by the seal member 92, even if the peripheral edge 91 does not form a perfect plane and is wavy, the unevenness can be favorably absorbed by the elastic deformation of the seal member 92, and the rocker chamber 6a and the outside are airtight. Sex can be reliably achieved. Further, in the internal combustion engine of the present invention, since the flange 86 and the step 82a of the upper end flange 82 are joined so as to also sandwich the peripheral edge 91 in the seal member 92, the peripheral edge 91, that is, the rocker cover 6 is formed. Mounting bolt 8 for connecting auxiliary port member 80 and intake manifold 84
5 also has the advantage that it can be easily and suitably fixed to the cylinder head 4 side.

[0029]

As described above in detail, according to the internal combustion engine of the first aspect of the present invention, the airtightness between the space between the cylinder head and the rocker cover and the outside is ensured by one seal member. To prevent oil mist and blow-by gas from leaking into the atmosphere, while ensuring airtightness between the auxiliary port of the auxiliary port member, the intake passage of the intake manifold and the outside, and high sealing performance. Therefore, the number of seal members can be reduced while reducing the cost and improving the assembling workability.

At this time, since the periphery of the opening is held between the seal members, vibration of the rocker cover accompanying vibration during operation of the internal combustion engine can be favorably absorbed by the seal members.
During operation, the rocker cover does not make contact noise with the auxiliary port member and the intake manifold.Furthermore, even if the periphery of the opening does not form a perfect plane and is wavy, the gap between the cylinder head and the rocker cover can be reduced. The airtightness between the space and the outside can be reliably achieved.

According to the internal combustion engine of the second aspect, the rocker cover can be suitably fixed to the cylinder head without using a fastener for separately attaching the rocker cover to the cylinder head.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an SOHC type direct injection gasoline engine according to the present invention.

FIG. 2 is a cross-sectional view of a seal member provided between a rocker cover, an auxiliary port member, and an intake manifold.

FIG. 3 is a view of the seal member attached to the rocker cover as viewed from a direction indicated by an arrow A in FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 engine 4 cylinder head 6 rocker cover 6a rocker chamber 34 intake port 80 auxiliary port member 80a auxiliary port 81 flange portion (first flange portion) 82 upper end flange portion (second flange portion) 84 intake manifold 84a internal passage 86 flange portion Third flange portion) 90 Opening hole 91 Peripheral edge 92 Seal member 93 Groove (cut)

Continued on the front page (72) Inventor Masahiro Fujimoto 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation

Claims (2)

[Claims] A rocker cover mounted on the cylinder head so as to cover a valve train disposed on an upper surface of the cylinder head, formed of a plate-shaped member, and having an opening; A seal member provided on the peripheral edge so as to sandwich the fuel cell from above and below, an intake port having one end communicating with the combustion chamber and the other end extending inside the cylinder head toward the upper surface of the cylinder head, and an auxiliary port inside. A first flange portion connected to the upper surface of the cylinder head is provided at one end so that the auxiliary port and the intake port communicate with each other, and the auxiliary port is opened at the other end facing the opening hole. An auxiliary port member provided with a second flange portion that is in contact with the seal member over the entire circumference, and an intake passage communicating with the auxiliary port through the opening hole therein. The internal combustion engine characterized by comprising an intake manifold third flange portion is provided which is connected to the second flange portion via the seal member over the entire periphery, the. 2. The seal member is fitted into a step formed over the entire periphery of one of the second flange portion and the third flange portion, and a peripheral edge of the opening hole is formed along with the seal member by the seal member. 2. The internal combustion engine according to claim 1, wherein the internal combustion engine is sandwiched between two flange portions and the third flange portion.